Mechanism of monitoring unit of electric rotating machinery and monitoring method of electric rotating machinery

ABSTRACT

A mechanism of a monitoring unit of an electric rotating machinery covered in a housing that intercepts photoelectron transmission, the mechanism has: a monitoring window penetrating a part of the housing and configured to allow passage of photoelectrons and not to allow passage of gas; a camera arranged outside the monitoring window and configured to receive radiated photoelectron generated in the housing and passing through the monitoring window and to generate image data from the radiated photoelectron; and a computing unit configured to process the image data. The computing unit has reference image data storage means for storing image data resulting from blackbody radiation occurring in a reference state in the housing, as reference image data, and temperature calculating means for comparing the image data with the reference image data, thereby to calculate the temperature in the housing.

TECHNICAL FIELD

The present invention relates to mechanism and method of monitoring thetemperature in the housing of electric rotating machinery, where thehousing to which photoelectron is intercepted.

BACKGROUND TECHNOLOGY

Monitoring method of a temperature of winding of electric rotatingmachinery is evaluated from the resistance value of the winding ofelectric rotating machinery have hitherto known. There is a method ofusing the sensor as other methods, such as a temperature measuringresistor or a thermocouple, is arranged near the winding, thereby tomeasure the temperature.

The method of the insulation diagnosis of winding of electric rotatingmachinery measures the size and frequency of the partial discharge pulsegenerated are hitherto known. There is a method of detecting a partialdischarge signal by using the static electric coupling of one specifiedphase and the other method is to detect a pulsating current signal by ahigh-frequency current transformer are known.

The method of detecting abnormal state of gas in the housing of electricrotating machinery is known. There is a method of extraction of gas incase, and measurement with macro analysis device.

The following three Patent Documents are known as disclosingspectroscopy analysis methods:

Patent Document 1: Japanese Patent Application Laid-Open Publication No.06-288922

Patent Document 2: Japanese Patent Application Laid-Open Publication No.07-198612

Patent Document 3: Japanese Patent Application Laid-Open Publication No.08-201361

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

The method of evaluating the temperature from the resistance value ofthe winding can indeed evaluate the average temperature of the entirewinding. However, the method cannot detect a local temperature change ofthe winding.

The method, in which a sensor, such as a temperature measuring resistoror a thermocouple, arranged near the winding, can detect a localtemperature rise in the winding. In the method of measuring thetemperature of neighborhood, abnormality in the measurement part can bedetected. However other abnormalities cannot be detected by the methodof measuring a part of temperature. If more temperature-measuringpositions are provided, as many sensors as the positions must beprovided. This will increase the cost.

The method of detecting a partial discharge signal by using the staticelectric coupling of one specified phase of the stator and the method ofdetecting a pulsating current signal by a high-frequency currenttransformer, it is difficult to detect it for the influence ofturbulence.

The abnormal state cannot be in real-time detected by method ofextraction of gas in the housing of electric rotating machinery andanalysis with macro analyzer.

Furthermore, the conventional techniques need to use a sensor fordetecting the temperature of electric rotating machinery, a sensor fordetecting the partial discharge and a sensor for analyzing the gas inthe housing.

The present invention has been made in consideration of the backgroundtechnology described above. An object of the invention is to detecteasily at least an abnormal temperature of electric rotating machinery.

Another object of the present invention is to detect easily theabnormality of partial discharge caused by deterioration of theinsulation in electric rotating machinery, almost in real-time. Afurther object of the invention is to analyze easily the gas in thehousing of electric rotating machinery. Still another object of theinvention is to detect the above-mentioned various conditions ofelectric rotating machinery, by using a single device.

Means for Solving the Problems

This invention is used to solve the problem in the above-mentioned.According to an aspect of the present invention, a mechanism ofmonitoring in a housing of electric rotating machinery, where thehousing to which photoelectron is intercepted, the mechanism comprising:a monitoring window penetrating a part of the housing and configured toallow passage of photoelectron and not to allow passage of gas; a cameraarranged outside the monitoring window and configured to receiveradiated photoelectron generated in the housing of electric rotatingmachinery and passing through the monitoring window and to generateimage data from the radiated photoelectron; and a computing unitconfigured to process the image data, wherein the computing unit hasreference image data storage means for storing image data resulting fromblackbody radiation occurring in a reference state in the housing ofelectric rotating machinery, as reference image data, and temperaturecalculating means for comparing the image data with the reference imagedata, thereby to calculate the temperature in the housing of electricrotating machinery.

There is also provided, according to another aspect of the presentinvention, a monitoring method of an electric rotating machinery coveredin a housing, where the housing to which photoelectron is intercepted,the method comprising: providing a monitoring window penetrating a partof the housing of electric rotating machinery and configured to allowpassage of photoelectron and not to allow passage of gas; arranging acamera outside the monitoring window, the camera configured to receiveradiated photoelectron generated in the housing and passing through themonitoring window and to generate image data from the radiatedphotoelectron; storing image data resulting from blackbody radiationoccurring in a reference state in the housing of electric rotatingmachinery, as reference image data; and comparing the image data withthe reference image data, thereby to calculate the temperature in thehousing of electric rotating machinery.

EFFECT IN THE INVENTION

The present invention can easily detect at least an abnormal temperatureof electric rotating machinery. Further more, if this invention is used,abnormality of partial discharge caused by deterioration of theinsulation, if any, in electric rotating machinery can be easilydetected almost in real time, the gas in the housing of electricrotating machinery can be easily analyzed, and the various conditions ofelectric rotating machinery can be detected by using a single device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is one execution chart of monitoring unit in the housing ofelectric rotating machinery when this invention is used; longitudinalsection model chart.

FIG. 2 is a block diagram showing the configuration of the photoelectronprocessing unit of the mechanism shown in FIG. 1 and the configurationof the components peripheral to the photoelectron processing unit.

FIG. 3 is a diagram explaining the photoelectron processing unit and theimage data about the components peripheral to the photoelectronprocessing unit.

FIG. 4 is a magnified, longitudinal sectional view of the attachedheater provided in the mechanism of monitoring the electric rotatingmachinery of FIG. 1.

FIG. 5 is a diagram representing the two-dimensional distribution ofincident photoelectron, which is observed while an object (auxiliarymember) remains not heated in the mechanism of FIG. 1.

FIG. 6 is a graph representing the relation between the wavelength andthe number of photoelectrons, which relation is observed in theembodiment of the mechanism according to the invention.

FIG. 7 is a graph representing the relation between the temperature andthe difference between the number of photoelectrons existing at thetemperature and the number of photoelectrons existing at a referencetemperature, which relation is observed in the embodiment of themechanism according to the invention.

FIG. 8 is a timing chart explaining how the attached heater isintermittently driven in the embodiment of the mechanism shown in FIG.1.

FIG. 9 is a diagram representing the two-dimensional distribution ofincident photoelectron to the photoelectron processing unit, which isobserved while the object remains heated in the mechanism of FIG. 1.

FIG. 10 is a graph representing the relation between the number ofphotoelectrons generated from the photoelectron emitting from the heatedobject of FIG. 9 and the wavelength.

FIG. 11 is a graph representing the difference between the data shown inFIG. 10 with the data inherent to the reference temperature, in terms ofthe number of photoelectrons and wavelength.

FIG. 12 is a graph representing the relation between the gasconcentration and the number of photoelectrons, which is used todetermine the gas concentration based on the data shown in FIG. 11.

FIG. 13 is a schematic longitudinal sectional view illustrating anotherpositional relation that the monitoring window, photoelectron processingunit and camera have in the mechanism of FIG. 1.

FIG. 14 is a schematic longitudinal sectional view showing a protectivecover secured to the junction between the monitoring window,photoelectron processing unit and camera, all shown in FIG. 13.

FIG. 15 is a schematic longitudinal sectional view showing a protectivecover which is different from the cover shown in FIG. 14 and which issecured to the junction between the monitoring window, photoelectronprocessing unit and camera, all shown in FIG. 14.

FIG. 16 is a schematic longitudinal sectional view showing how thecamera and the computing unit are connected in a modification of themechanism shown in FIG. 1.

EXPLANATION OF REFERENCE SYMBOLS

1 Housing

2 Stator

4 Winding end point

5 Monitoring window

6 Photoelectron processing unit

7 Camera

7 a First spectroscopy-image camera

7 b Second spectroscopy-image camera

7 c 2D-image camera

8 Cable

9 Computing unit

10 Photomultiplier

11 Photoelectron distributor

12 First photoelectron condenser

13 Second photoelectron condenser

14 First spectrometer

15 Second spectrometer

20 First optical path

21 Second optical path

22 Third optical path

23 First partial mirror

24 Second partial mirror

24 a Opening

25 Attached heater (auxiliary-member heating unit)

26 Electric heater

27 Heater power supply

28 Heated object (auxiliary member)

29 Surface-temperature sensor

30 Surface-temperature measuring unit

50 Holder

51, 52, 53 Junction protective covers

60 Transmitter

61 Receiver

62 Transmission path

70, 71: Image data

Best Mode Embodiment For Carrying Out The Invention

An embodiment of mechanism of monitoring unit and monitoring method ofelectric rotating machinery, both according to the present invention,will be described with reference to the accompanying drawings.

An embodiment of mechanism of monitoring unit and monitoring method ofelectric rotating machinery, according to this embodiment, will bedescribed with reference to FIG. 1 to FIG. 4. FIG. 1 is one executionchart of monitoring unit in the housing of electric rotating machinerywhen this invention is used; longitudinal section model chart. FIG. 2 isa block diagram showing the configuration of the photoelectronprocessing unit of the mechanism shown in FIG. 1 and the configurationof the components peripheral to the photoelectron processing unit. FIG.3 is a diagram explaining the photoelectron processing unit and theimage data about the components peripheral to the photoelectronprocessing unit. FIG. 4 is a magnified, longitudinal sectional view ofthe auxiliary-member heater (attached heater) provided in the mechanismof monitoring unit of the electric rotating machinery.

The electric rotating machinery shown in FIG. 1 is, for example, anelectric motor. The electric rotating machinery comprises a housing(frame) 1 and a stator 2. The stator 2 is arranged in the housing(frame) 1. The housing 1 is made of, for example, steel, and covers theentire stator 2. The housing 1 is configured to interceptphotoelectrons. The housing 1 has an opening made in a part near thewinding end point 4 of the stator 2. In this opening, a monitoringwindow 5 is fitted, closing the opening. The monitoring window 5 isconfigured to allow the passage of photoelectrons, but not the passageof gas. The monitoring window 5 can remain intact even if an explosionoccurs in the housing 1.

A photoelectron processing unit 6 is provided outside the monitoringwindow 5. The photoelectron processing unit 6 generates information,which is input to a camera 7. The camera 7 generates image data. Theimage data is supplied from the camera 7, in the form of a signal,through a cable 8 to a computing unit 9. The computing unit 9 processesthe signal.

As shown in FIG. 2 and FIG. 3, the photoelectron processing unit 6 has aphotomultiplier 10, a first optical path 20 and a photoelectrondistributor 11. The photomultiplier 10 generates more photoelectronsthan the photoelectrons it has received. The photoelectron distributor11 receives photoelectrons from the photomultiplier 10 and distributesthe electrons to a first optical path 20, a second optical path 21 and athird optical path 22. The photoelectron processing unit 6 further has afirst photoelectron condenser 12, a second photoelectron condenser 13, afirst spectrometer 14, and a second spectrometer 15. The firstphotoelectron condenser 12 condenses the photoelectrons coming throughthe first optical path 20. The second photoelectron condenser 13condenses the photoelectrons coming through the second optical path 21.The first spectrometer 14 receives photoelectrons from the firstphotoelectron condenser 12 and splits the photoelectrons into beams ofdifferent wavelengths. The second spectrometer 15 receivesphotoelectrons from the second photoelectron condenser 13 and splits thephotoelectrons into beams of different wavelengths.

The two photoelectron beams emerging from the first spectrometer 14 andsecond spectrometer 15, respectively, are applied to a firstspectroscopy-image camera 7 a and a second spectroscopy-image camera 7b, respectively. The first spectroscopy-image camera 7 a generates imagedata, and the second spectrometer 7 b generates image data. Thephotoelectron beam emerging from the photoelectron distributor 11 to thethird optical path 22 is applied to a 2D-image camera 7 c, whichgenerates image data. In FIG. 1, the cameras 7 a and 7 b are illustratedas one camera 7.

The photoelectron distributor 11 is configured to distributephotoelectrons. The photoelectron distributor 11 incorporates a firstpartial mirror (half mirror) 23 and a second partial mirror 24. Thefirst partial mirror 23 is semitransparent (translucent) in itsentirety, allowing passage of a part (not necessarily, exactly a half)of the incident photoelectrons and not allowing the passage of theremaining part of the incident photoelectrons. That part of thephotoelectrons, which have passed through the first partial mirror 23,enter the third optical path 22. The remaining part of thephotoelectrons are reflected by the first partial mirror 23, are appliedto the second partial mirror 24. The second partial mirror 24 has anopening 24 a in the center part. A part of the photoelectrons applied tothe second partial mirror 24 pass through the opening 24 a and thenenter the second optical path 21. The other part of the photoelectrons,which are applied to the peripheral part of the second partial mirror24, are reflected by the second partial mirror 24 and travel through thefirst optical path 20.

As shown in FIG. 1, the electric rotating machinery further has anattached heater 25. The attached heater 25 penetrates the housing 1,secured to that part thereof which is near the monitoring window 5.

As shown in FIG. 4, the attached heater 25 has an electric heater 26, aheater power supply 27, a heated object 28, a surface-temperature sensor29, and a surface-temperature measuring unit 30. The heater power supply27 supplies electric power to the electric heater 26. The electricheater 26 heats the heated object (auxiliary member) 28. Thesurface-temperature sensor 29 is designed to detect the surfacetemperature of the heated object 28. The heated object 28 is made ofmetal such as copper or aluminum. As FIG. 1 shows, the heated object 28is so located that the camera 7 may photograph it through the monitoringwindow 5.

The mechanism of the monitoring unit of the electric rotating machinery,which is so configured as described above, operates as will be describedbelow.

It will be first explained how the mechanism operates while the attachedheater 25 remains not driven. This is the case where the heater powersupply 27 does not operate at all, or where the attached heater 25 isnot provided at all.

Generally, the radiant light (i.e., electromagnetic wave) radiated froman object has an intensity that is a function of the surface temperatureof the object. Hence, the temperature of the object can be estimated ifthe intensities of light beams emitting from various points in thesurface of the object are compared with the intensities of light beamsemitting from those points while the object has a reference temperature.The word “light” used here means not only visible light, but alsoelectromagnetic waves such as infrared rays and ultraviolet rays.

Partial discharge may occur due to insufficient insulation of the statorwinding of the electric rotating machinery. The partial dischargeresults in electromagnetic waves. Therefore, abnormality of partialdischarge, if any, in electric rotating machinery can be detected fromthe electromagnetic waves generated in the electric rotating machinery.

Using this principle, in this embodiment, the electromagnetic wavesemitting from the electric rotating machinery is detected, and thetemperatures of various components are determined from theelectromagnetic waves, thereby detecting the abnormality of partialdischarge.

Assume that the camera 7 photographs the blackbody radiation from thewinding end point 4 of the stator 2 of the electric rotating machinery,through the monitoring window 5 in the axial direction of the stator 2.Then, such image data 70 as shown in FIG. 5 are obtained. The radiationfrom the high-temperature part of the winding end point 4 of the stator2 is intense. This means that the high-temperature part of the windingend point 4 is radiating intense light. From the image, which part ofthe electric rotating machinery emits intense light can therefore bedetermined. That part of the image, which is specified by an ellipse“A”, emits an electromagnetic wave far stronger than the wave emittingfrom the other winding end point of the stator. This shows that coronadischarge may be taking place at the high-temperature part, due toinsufficient insulation at that part. Thus, such abnormality can beeasily determined by comparing the image data with the reference imagedata acquired in normal state and saved in a storage device. The imagedata is acquired through the third optical path 22 shown in FIG. 3.

Of the image data 70 shown in FIG. 5, the part specified by an ellipse“B”, for example, are supposed to radiate an intense electromagneticwave and therefore to have high temperature. The temperature of thispart is determined from the intensity of the electromagnetic wave. Inthis case, the light traveling through the first optical path 20 iscondensed by the first photoelectron condenser 12, and the firstspectrometer 14 splits the light into electromagnetic wave components ofdifferent wavelengths. One or some of these wave components areselected. Preferably, the selected wave or each selected wave componentis compared with the reference wave component of the same wavelength,which has been generated at a reference temperature.

FIG. 6 shows a wavelength distribution curve 33 for the number ofphotoelectrons generated through radiation at the reference temperatureof, for example, 20 degrees centigrade, and a wavelength distribution 34for the number of photoelectrons generated through radiation at thetemperature N degrees centigrade measured. If N>20, more photoelectronsare generated through the radiation at the temperature N degreescentigrade than through the radiation at the reference temperature (20degrees centigrade), as seen from FIG. 6. Let F1 denote a difference interms of the number of photoelectrons, for a wavelength L1, and F2denote a difference in terms of the number of photoelectrons, foranother wavelength L2. F1 and F2 have positive values if the temperatureN degrees centigrade is higher than the reference temperature.

The relation between the difference F1 for wavelength L1 and thedifference between the measured temperature and the referencetemperature can be illustrated as, for example, the solid line 35 shownin FIG. 7. Similarly, the relation between the difference F2 forwavelength L2 and the difference between the measured temperature andthe reference temperature can be illustrated as, for example, the brokenline 36 shown in FIG. 7. As seen from the solid line 35 and the brokenline 36, the difference of both the number of photoelectrons at thereference temperature (20 degrees centigrade) are, of course, zero.

At the reference temperature and various temperatures measured,respectively, the numbers of photoelectrons resulting from the radiationcan be measured, preparing both FIG. 6 and FIG. 7, and the datarepresenting FIGS. 6 and 7 may be stored in the storage device. When thetemperature of the electric rotating machinery is measured actually, thenumber of photoelectrons may be first determined and the temperature maythen be estimated from the number of photoelectrons, based on therelations shown in FIG. 7. In this case, the temperature can indeed beestimated from the number of photoelectrons for one wavelength. Instead,the temperatures may first be estimated from the data items aboutvarious wavelengths and the temperatures thus estimated may then becompared, thereby making the data more reliable. Alternatively, thetemperatures estimated from the data items may be averaged, therebyrendering the data more reliable.

How the attached heater (auxiliary-member heating unit) 25 operates inthe mechanism of monitoring the electric rotating machinery will beexplained. The attached heater 25 cooperates with some other componentsof the mechanism, such as the photoelectron processing unit 6 and thecamera 7, to detect the abnormal gas generation in the housing 1 of theelectric rotating machinery and to determine the concentration of thegas generated in the housing 1.

The heated object (auxiliary member) 28 is attached to the electricheater 26 inserted in the housing 1. The heater power supply 27 suppliespower to the electric heater 26 on and off, whereby the heated object 28is alternately heated and cooled, repeatedly. While the heated object 28is being cooled, the gas in the housing 1 is applied to the surface ofthe heated object 28, forming a layer of gas material. When the heatedobject 28 is then heated, the gas-material layer is gasified. At thispoint, an electromagnetic wave emits from the heated object 28. Thiselectromagnetic wave is analyzed, detecting the composition andconcentration of the gas in the housing 1.

FIG. 8 is a timing chart explaining how the attached heater 25 isintermittently driven in an example of the measuring step. As shown inFIG. 8, the heated object 28 is repeatedly heated on and off, each timefor 10 minutes, heated for five minutes and then cooled for fiveminutes. While the heated object 28 is being heated, data aboutphotoelectrons is acquired.

FIG. 9 is a diagram showing image data 71 of photoelectrons input to thephotoelectron processing unit 6 every time the heated object 28 isheated on as shown in FIG. 8. In FIG. 9, ellipse B specifies a part thatemits an electromagnetic wave corresponding to the heat emitting fromthe winding end point 4 of the stator 2 of the electric rotatingmachinery, and ellipse A specifies a part that emits an electromagneticwave due to abnormal discharge, as in the case of FIG. 5. In FIG. 9,ellipse “C” specifies a part that emits an electromagnetic wave, too.This part radiates an electromagnetic wave that corresponds to the heatradiating from the heated object 28.

FIG. 10 is a graph representing the relation between the number ofphotoelectrons and the wavelength, both pertaining to theelectromagnetic wave emitting from part C in FIG. 9, i.e., heated object28. This distribution curve consists of a distribution curve 40 that isas gentle as the distribution curve shown in FIG. 6, and a peaks 14 atsome wavelengths. The gentle distribution curve 40 is a distributioncurve for a specific temperature, or similar to the curves shown in FIG.6.

On the other hand, the peaks 41 result from the radiations thatcorrespond to the materials attached to, heated on and emitted from thesurface of the heated object 28. The wavelengths at which the peaks 41are observed (i.e., specific leak wavelengths) pertain to the kinds ofgases. Hence, the gases can be identified with the wavelengths at whichthe peaks 41 are observed.

The heights of the peaks 41 may be measured. From the heights of peaks41, the concentrations of gas components in the housing 1 can bedetermined.

FIG. 11 is a graph showing the difference between the data shown in FIG.10 with the data inherent to the reference temperature, in terms of thenumber of photoelectrons and wavelength. In the case shown in FIG. 11,the number of photoelectrons sharply increases at three wavelengths Q1,Q2 and Q3. This graph may be compared with the data specific to thereference temperature, thereby to determine the numbers D1, D2 and D3 ofphotoelectrons which are specific to wavelengths Q1, Q2 and Q3,respectively. Increases in the photoelectrons which are specific tovarious known gas concentrations corresponding to wavelengths Q1, Q2 andQ3 are then measured, and such relations between the gas concentrationsand the photoelectron numbers as shown in FIG. 12 (i.e., calibrationcurves) are obtained to store the data. Then, the number ofphotoelectrons actually resulting from the electromagnetic wavegenerated in the electric rotating machinery is measured and comparedwith each of the calibration curves. Thus, the number of photoelectronscan be converted to the gas concentration that corresponds to a specificwavelength.

In the configuration described above, the electric heater 26 and theheated object 28 are two different members. Nonetheless, the heatedobject 28 may be an electrical resistor. If this is the case, theelectric heater 26 and the heated object 28 can be integrated into onemember.

If an abnormal temperature of the electric rotating machinery, abnormaldischarge, or abnormal as generation in the housing is detected asdescribed above, an alarm may be generated.

FIG. 13 illustrates a modification of the configuration for securing thephotoelectron processing unit 6 to the monitoring window 5 in themechanism of the monitoring unit of the electric rotating machinery,which is shown in FIG. 1. As shown in FIG. 13, the photoelectronprocessing unit 6 is obliquely secured to the monitoring window 5. Inthis case, a holder 50 is attached to the housing 1 or the monitoringwindow 5, preventing photoelectrons from leaking at the junction betweenthe unit 6 and the window 5. In the case of FIG. 14, not only thephotoelectron processing unit 6 is obliquely secured to the monitoringwindow 5, but also a junction protective cover 51 surrounds the junctionbetween the window 5 and the unit 6 and the junction between the unit 6and the camera 7. FIG. 15 shows a modification of the configuration ofFIG. 14. As FIG. 15 shows, two junction protective covers 52 and 53 areused. The cover 52 covers the junction between the monitoring window 5and the photoelectron processing unit 6, while the cover 53 covers thejunction between the photoelectron processing unit 6 and the camera 7.Still another modification is to fill the gap with putty or to solderthe junction, instead of using a junction protective cover or covers.

FIG. 16 shows a signal path extending between the camera 7 and thecomputing unit 9, which differs from those shown in FIG. 1 and FIG. 13.In this instance, a transmitter 60 and a receiver 61 are arranged at thecamera 7 and the computing unit 9, respectively, and a transmission path62 connects the transmitter 60 and the receiver 61. The transmissionpath 62 may be replaced by radio transmission.

1. A mechanism of monitoring a unit of an electric rotating machinery ina housing from which photoelectrons are intercepted by a camera, themechanism comprising: a monitoring window penetrating a part of thehousing and configured to allow passage of the photoelectrons and not toallow passage of gas; a camera arranged outside of the monitoring windowand configured to receive the radiated photoelectrons generated in thehousing of the electric rotating machinery and passing through themonitoring window, and to generate image data from the radiatedphotoelectrons; and a computing unit configured to process the imagedata, wherein the computing unit has reference image data storage meansfor storing the image data resulting from blackbody radiation occurringin a reference state in the housing of the electric rotating machineryas reference image data, and temperature calculating means for comparingthe image data with the reference image data, thereby to calculate thetemperature in the housing of the electric rotating machinery.
 2. Themechanism of the monitoring unit of the electric rotating machineryaccording to claim 1, further comprising a photomultiplier configured toconvert the radiated light coming through the monitoring window tophotoelectrons, thereby multiplying the photoelectrons, and to apply thephotoelectrons to the camera.
 3. The mechanism of the monitoring unit ofthe electric rotating machinery according to claim 1, wherein thecomputing unit includes means for comparing the image data with thereference image data, thereby to determine generation of an abnormalelectromagnetic wave in the housing and determine the position where theabnormal electromagnetic wave is generated.
 4. The mechanism of themonitoring unit of the electric rotating machinery according to claim 1,wherein a cable connects the camera and the computing unit.
 5. Themechanism of the monitoring unit of the electric rotating machineryaccording to claim 1, wherein a transmitter is attached to the camera inorder to transmit the image data, and a receiver is attached to thecomputing unit in order to receive the image data transmitted from thecamera.
 6. The mechanism of the monitoring unit of the electric rotatingmachinery according to claim 1, further comprising a protective coverconfigured to suppress entry of photoelectrons to a gap between themonitoring window and the camera.
 7. The mechanism of the monitoringunit of the electric rotating machinery according to claim 1, whereinthe computing unit further has an alarm device configured to generate analarm when the image data differs from the reference image data by avalue greater than a prescribed width.
 8. The mechanism of themonitoring unit of the electric rotating machinery according to claim 1,further comprising a spectrometer for splitting the radiatedphotoelectrons coming through the monitoring window into photoelectronbeams of different wavelengths, wherein the temperature calculatingmeans compares the image data with the reference image data with respectto at least one beam of a specific wavelength, thereby to calculate thetemperature in the housing.
 9. The mechanism of the monitoring unit ofthe electric rotating machinery according to claim 8, wherein thetemperature calculating means compares the image data with the referenceimage data with respect to at least two beams of specific wavelengths,thereby to calculate temperatures in the housing, and includes a meansfor finding an average of the temperatures calculated.
 10. The mechanismof the monitoring unit of the electric rotating machinery according toclaim 1, further comprising: a heated object arranged in the housing andat a position to be heated and monitored through the monitoring windowby the camera; a heater configured to heat the heated object; and athermometer configured to measure the temperature of the heated objectthus heated, wherein the computing unit further includes specificwavelength-peak extracting means for comparing the wavelengthdistribution of the image data acquired when the heater heats the heatedobject, evaporating a material sticking to the heated object, with thewavelength distribution of the reference image data, thereby to extractspecific peak wavelengths.
 11. The mechanism of the monitoring unit ofthe electric rotating machinery, according to claim 10, wherein thecomputing unit includes means for determining the composition of the gasin the housing from the specific peak wavelengths.
 12. The mechanism ofthe monitoring unit of the electric rotating machinery according toclaim 11, wherein the computing unit further includes means fordetermining the concentration of a specific gas component in the housingfrom the intensities of radiated photoelectron beams of the specificpeak wavelengths of the image data.
 13. A monitoring method of anelectric rotating machinery covered in a housing from whichphotoelectrons are intercepted, the method comprising: providing amonitoring window penetrating a part of the housing of the electricrotating machinery and configured to allow passage of photoelectrons andnot to allow passage of gas; arranging a camera outside of themonitoring window, the camera configured to receive radiatedphotoelectrons generated in the housing and passing through themonitoring window, and to generate image data from the radiatedphotoelectrons; storing image data resulting from blackbody radiationoccurring in a reference state in the housing of the electric rotatingmachinery as reference image data; and comparing the image data with thereference image data, thereby to calculate the temperature in thehousing of the electric rotating machinery.
 14. The method of monitoringelectric rotating machinery according to claim 13, wherein aphotomultiplier converts the radiated light coming through themonitoring window to photoelectrons, thereby multiplying the light, andapplies the photoelectrons to the camera.
 15. The method of monitoringelectric rotating machinery according to claim 13, wherein the imagedata is compared with the reference image data, thereby to determinegeneration of an abnormal electromagnetic wave in the housing and todetermine a position where the abnormal electromagnetic wave isgenerated.
 16. The method of monitoring electric rotating machineryaccording to claim 13, wherein the radiated photoelectrons comingthrough the monitoring window are split into photoelectron beams ofdifferent wavelengths, and the image data is compared with the referenceimage data with respect to at least one beam of a specific wavelength,thereby to calculate the temperature in the housing.
 17. The method ofmonitoring electric rotating machinery according to claim 16, whereinthe image data is compared with the reference image data with respect toat least two beams of specific wavelengths, thereby to calculatetemperatures in the housing, and an average of the temperaturescalculated is calculated.
 18. The method of monitoring electric rotatingmachinery according to claim 13, further comprising: arranging a heatedobject in the housing and at a position to be heated and monitoredthrough the monitoring window by the camera; heating the heated objectintermittently; measuring the temperature of the heated object thusheated; comparing the wavelength distribution of the image data acquiredwhen the heated object is heated, to evaporate a material sticking tothe heated object, with the wavelength distribution of the referenceimage data, thereby to extract specific peak wavelengths; anddetermining the composition of the gas in the housing from the specificpeak wavelengths.
 19. The method of monitoring electric rotatingmachinery according to claim 18, wherein the concentration of a specificgas component in the housing is determined from the intensities ofradiated photoelectron beams of the specific peak wavelengths of theimage data.